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Evaluation of cell morphology by video recording and computer-assisted image analysis.

The aim of this study was to evaluate the effects of various cell culture conditions on cell morphology. Cell morphology was estimated by means of video recording and computer-assisted image analysis. Cell contours from the stored images of either live cells or fixed and stained cells were determined automatically, and cellular area, form factor, and average cell brightness were calculated. Using the mouse fibroblastoid L 929 cell line (L-cells) and the rat glioma BT4C cell line, it was found that a number of methodological parameters strongly affected cell morphology. These included confluency of cells before dissociation, dissociation procedure, cell seeding density, cultivation time, and culture substratum. The substratum, particularly collagen type I and fibronectin, profoundly affected cell morphology. Using drugs affecting cytoskeletal organization or cell substratum interactions, it was shown that average cell brightness was a valuable parameter for estimation of cellular attachment. Cytochalasin D, which impairs actin filaments, caused a dramatic increase in the average cell brightness in both cell lines. Nocodazole, which depolymerizes microtubules, mainly affected the L-cells, whereas the BT4C-cells were largely unaffected, indicating that microtubules were morphological determinants for the former cell line but not for the latter. When cells were grown on fibronectin, an RGD-peptide only affected L-cell attachment, indicating that BT4C-cells only expressed low (if any) amounts of RGD recognizing integrins. The interassay precision of the employed procedure depended on culture substratum; the coefficients of variation ranged from 7-24%. Lowest variations in area determination were found for cells grown on fibronectin. The coefficient of variation of form factor determinations was generally around 20%, independent of substrata and culture time.

Animals↗

Assessing swine thermal comfort by image analysis of postural behaviors.

Postural behavior is an integral response of animals to complex environmental factors. Huddling, nearly contacting one another on the side, and spreading are common postural behaviors of group-housed animals undergoing cold, comfortable, and warm/hot sensations, respectively. These postural patterns have been routinely used by animal caretakers to assess thermal comfort of the animals and to make according adjustment on the environmental settings or management schemes. This manual adjustment approach, however, has the inherent limitations of daily discontinuity and inconsistency between caretakers in interpretation of the animal comfort behavior. The goal of this project was to explore a novel, automated image analysis system that would assess the thermal comfort of swine and make proper environmental adjustments to enhance animal wellbeing and production efficiency. This paper describes the progress and on-going work toward the achievement of our proposed goal. The feasibility of classifying the thermal comfort state of young pigs by neural network (NN) analysis of their postural images was first examined. It included exploration of using certain feature selections of the postural behavioral images as the input to a three-layer NN that was trained to classify the corresponding thermal comfort state as being cold, comfortable, or warm. The image feature selections, a critical step for the classification, examined in this study included Fourier coefficient (FC), moment (M), perimeter and area (P&A), and combination of M and P&A of the processed binary postural images. The result was positive, with the combination of M and P&A as the input feature to the NN yielding the highest correct classification rate. Subsequent work included the development of hardware and computational algorithms that enable automatic image segmentation, motion detection, and the selection of the behavioral images suitable for use in the classification. Work is in progress to quantify the relationships of postural behavior and physiological responses of pigs using thermographs. The results are expected to facilitate objective training of NN, hence improving the accuracy of the postural image-based assessment of the thermal comfort state. Work is also in progress to implement the analysis and assessment algorithms into computer codes for real-time application.

Animal Welfare↗

Ductoscopic cytology and image analysis to detect breast carcinoma.

BACKGROUND: The goal of the prospective study was to determine whether 1) image analysis (IA; including DNA index [DI], S-phase fraction, and the presence or absence of aneuploidy or hypertetraploidy [HT]) of fiberoptic ductoscopy (FD) breast specimens was feasible, 2) IA findings from FD specimens predicted histopathologic evidence of disease, and 3) a combination of IA, cytology, and clinical factors provided complementary information in the diagnosis of breast carcinoma. METHODS: IA and cytologic evaluation were performed on 106 consecutively collected ductoscopic specimens from 88 subjects. RESULTS: IA was successful in 73 (71%) FD specimens. HT (P = 0.03) was related to intraductal visual observations. The proportion of atypical papillomas with aneuploidy was greater (P = 0.05) than in any other class. The HT index was higher in atypical papilloma (P = 0.02) and in breast carcinoma (P = 0.05) than with other diagnoses. The proportion of papilloma cases with HT was greater (P = 0.04) than benign papillomas. Malignant cytology was associated with a higher DI (P = 0.02) and a higher HT index (P = 0.001) than nonmalignant (benign or atypical) cytology. HT (P = 0.002) was less common with cytology containing few epithelial cells, and the HT index was higher with malignant versus nonmalignant FD cytology (P = 0.001). The percentage of cells containing HT was greater in FD specimens that were suspicious for malignancy (P = 0.006) than in those with benign cytology or mild atypia. Considering all samples and combining IA, cytologic, and visual findings in a stepwise linear discriminant analysis optimized the sensitivity (61%) and specificity (90%) of breast carcinoma prediction. Excluding spontaneous nipple discharge (SND) samples and adding epithelial cell quantity in samples improved the model (sensitivity, 85%; specificity, 80%). CONCLUSIONS: IA was feasible in FD specimens whenever adequate epithelial cells were present. IA and cytologic findings were associated. Adding IA results to cytology and visual findings and excluding samples with SND improved diagnostic sensitivity.

Aneuploidy↗

Epi-fluorescence microscopy and image analysis used to measure diffusion coefficients in gel systems.

A method using epi-fluorescence microscopy and image analysis has been developed to follow and quantify the diffusion of fluorescent compounds through gels. Two mathematical approaches were employed to calculate diffusion coefficients. The spatial resolution provided by the fluorescence microscope allowed diffusion to be followed over very short distances; accordingly diffusion coefficients were obtained within minutes, even for slowly diffusing systems. The method was successfully applied to the diffusion of macromolecules into agar, carbopol and mucus gel systems.

Algorithms↗

Coordinate-based versus structural approaches to brain image analysis.

A basic issue in neurosciences is to look for possible relationships between brain architecture and cognitive models. The lack of architectural information in magnetic resonance images, however, has led the neuroimaging community to develop brain mapping strategies based on various coordinate systems without accurate architectural content. Therefore, the relationships between architectural and functional brain organizations are difficult to study when analyzing neuroimaging experiments. This paper advocates that the design of new brain image analysis methods inspired by the structural strategies often used in computer vision may provide better ways to address these relationships. The key point underlying this new framework is the conversion of the raw images into structural representations before analysis. These representations are made up of data-driven elementary features like activated clusters, cortical folds or fiber bundles. Two classes of methods are introduced. Inference of structural models via matching across a set of individuals is described first. This inference problem is illustrated by the group analysis of functional statistical parametric maps (SPMs). Then, the matching of new individual data with a priori known structural models is described, using the recognition of the cortical sulci as a prototypical example.

Brain↗

Direct quantification of in vitro cell growth through image analysis.

Objective, accurate, non-intrusive measurement of in vitro cell growth was realized through microcomputerized video image analysis. Recently-released video and digitizing hardware and software were incorporated into an analytical system which accurately quantified visual differences between cultures on a cell number or fresh mass basis. Sequential measurements during culture incubation further detected and quantified subtle changes in colony area and density resulting from growth. Each measurement was acquired rapidly, without encroaching on the in vitro environment, so cell growth was undisturbed. Custom software routines coordinated the quantification of this detailed record into precise cumulative growth curves.

Cell Division↗

A comparative study of DNA ploidy in 115 fresh-frozen breast carcinomas by image analysis versus flow cytometry.

BACKGROUND: Qualitative and quantitative analysis of cellular DNA content may be clinically useful in the prognostic evaluation of certain types of malignant tumors, including breast carcinoma. Flow cytometric (FCM) analysis has been the most frequently used procedure for DNA analysis, but it requires a reasonably large tissue sample. Computer-based image analysis (IA) now allows imprint, cytospin, and needle aspiration smear preparations and other small tissue samples to be used. METHODS: To resolve concern about the diagnostic efficacy of small tissue samples in the use of IA, the authors performed a comparative study of FCM analysis and IA using 115 fresh-frozen breast carcinomas. Feulgen-stained imprint preparations for IA and single-cell suspensions from the same fresh-frozen tissue for FCM analysis were used, and the respective histograms were compared. RESULTS: The results were concordant in 90.4% (104 of 115) of the cases, but 11 specimens yielded discordant data. IA provided histograms with a somewhat lower resolution and a relatively high coefficient of variation for the G0/G1 peak, thus rendering occasional tumors, which were near-diploid aneuploid by FCM analysis (four cases), not amenable to diagnosis by aneuploid characterization. In three additional cases, FCM analysis showed aneuploid hyperdiploid (two cases) and multiploid (one case) histograms, but IA only demonstrated a diploid peak. Conversely, in four other cases, aneuploid peaks were recognized only by IA. CONCLUSIONS: Computerized IA has significant advantages over FCM analysis, including lower cost, the ability to analyze very small specimens, the capability of detecting rare high ploidy cells, the capacity to classify cellular populations according to specific morphologic type, and the fact that no destructive enzyme or chemical digestion is required for specimen preparation, thereby preserving the integrity of fragile cells.

Breast Neoplasms↗

Automated digital image analysis of organ culture preserved donor corneas.

The present study reports the application of a modified commercially available automated digital image analysis system (DIA) for the evaluation of organ culture preserved donor corneas. The central corneal endothelium was viewed and photographed under an inverted phase-contrast microscope. The images were then analyzed with the help of DIA. The results of DIA were compared to the findings obtained with a conventional 'fixed-frame analysis' for the same corneas. 100 human donor corneas have been evaluated. DIA, with interactive picture enhancement, was found to be practicable, and to yield reproducible results. The mean number of cells analyzed per photograph was 250 (range 95-395); this, on the average, was four times higher than with conventional fixed-frame analysis (mean 54, range 37-70). The correlation of the cell densities obtained with both methods was highly significant (p < 0.0001). Since additional information, like variation in cell size and shape (circularity form factor), was automatically computed by the program, more data on the homogeneity of the donor endothelial cell pattern were available. Furthermore, this computerized technique does not require an experienced investigator and thereby helps to eliminate bias.

Cell Count↗

Static image analysis of skin specimens: the application of telepathology to frozen section evaluation.

Although the ability to transmit high-resolution images of histopathological sections could have a profound impact on the practice of pathology, the application of video microscopy to the daily activities of surgical pathology has not been rigorously evaluated. In particular, certain aspects of video microscopy relating to frozen section evaluation have not been adequately assessed. We conducted a retrospective analysis of 48 excisional skin biopsy specimens encompassing a spectrum of benign and malignant lesions. To simulate an actual frozen section evaluation, only original frozen section slides were evaluated. Fields were selected and digitized (Roche Image Analysis System) by a pathology resident. Two sets of diagnoses were subsequently rendered by a surgical pathologist, the first set based on the digitized images and the second based on direct microscopic examination of the histological slides. The two sets of diagnoses were compared, and the concordance rates were as follows: malignant diagnoses, 100%; benign diagnoses, 100%; positive margins, 96%; negative margins, 99%. One (4%) of the 25 positive margins was indexed as negative by image analysis. Conversely, one (1%) of the 121 negative margins was indexed as positive by image analysis. In both of these cases, error was attributable to selection and digitization of an inappropriate field. We conclude that telepathology of static images is an accurate method of evaluating frozen sections of skin lesions. Potentially, this technology could be applied to the frozen section evaluation of other lesions as well. Static image analysis is, however, susceptible to errors induced by inappropriate field selection, emphasizing the need for trained and skillful personnel on both sides of the video camera.

Frozen Sections↗

Evaluation of the mastascanelite image analysis system for measuring zones of inhibition in disc diffusion susceptibility tests.

In this evaluation a mastascanelite image analysis system is compared with manual measurement of disc diffusion inhibition zones. Data for 213 diverse organisms and a total of 1679 organism/antibiotic combinations gave an overall correlation coefficient of 0.988. The mean difference between readings was +0.425 mm, with 95% confidence limits of +/-2.94 mm, and the majority of scanned zones (97.51%) fell within +/-3 mm of the manual measurement. The mastascanelite system forms part of a laboratory suite and was found to be objective, accurate and rapid, reading and interpreting each plate in less than a second. Interfacing to the laboratory computer system facilitated data handling and performance control.

Bacteria↗

Biomass quantification by image analysis.

Microbiologists have always rely on microscopy to examine microorganisms. When microscopy, either optical or electron-based, is coupled to quantitative image analysis, the spectrum of potential applications is widened: counting, sizing, shape characterization, physiology assessment, analysis of visual texture, motility studies are now easily available for obtaining information on biomass. In this chapter the main tools used for cell visualization as well as the basic steps of image treatment are presented. General shape descriptors can be used to characterize the cell morphology, but special descriptors have been defined for filamentous microorganisms. Physiology assessment is often based on the use of fluorescent dyes. The quantitative analysis of visual texture is still limited in bioengineering but the characterization of the surface of microbial colonies may open new prospects, especially for cultures on solid substrates. In many occasions, the number of parameters extracted from images is so large that data-mining tools, such as Principal Components Analysis, are useful for summarizing the key pieces of information.

Algorithms↗

[Measurement of retinal circulation times in non-proliferative diabetic retinopathy by use of fluorescein video angiography and image analysis system].

Retinal circulation times were measured in all measurable retinal areas using fluorescein video angiography and image analysis systems. The subjects cornsted of 16 non-proliferative diabetic retinopathy eyes and 31 normal eyes. In the diabetic eyes no non-perfusion area was found on fluorescein angiograms. Retinal circulation times were measured when 16%, 33%, 50%, 66% or 83% of the total fluorescence volume was reached. Measured retinal areas consisted of 61 areas in diabetic eyes and 120 areas in normal eyes. Retinal circulation times of 50% and under flowed were found significantly shorter in the diabetic eyes than in the normal eyes (p less than 0.03). These results showed that blood flow volume of the shorter way in retinal circulation might increase in non-proliferative diabetic retinopathy.

Adult↗

Robust active appearance models and their application to medical image analysis.

Active appearance models (AAMs) have been successfully used for a variety of segmentation tasks in medical image analysis. However, gross disturbances of objects can occur in routine clinical setting caused by pathological changes or medical interventions. This poses a problem for AAM-based segmentation, since the method is inherently not robust. In this paper, a novel robust AAM (RAAM) matching algorithm is presented. Compared to previous approaches, no assumptions are made regarding the kind of gray-value disturbance and/or the expected magnitude of residuals during matching. The method consists of two main stages. First, initial residuals are analyzed by means of a mean-shift-based mode detection step. Second, an objective function is utilized for the selection of a mode combination not representing the gross outliers. We demonstrate the robustness of the method in a variety of examples with different noise conditions. The RAAM performance is quantitatively demonstrated in two substantially different applications, diaphragm segmentation and rheumatoid arthritis assessment. In all cases, the robust method shows an excellent behavior, with the new method tolerating up to 50% object area covered by gross gray-level disturbances.

Algorithms↗

A computer-assisted image-analysis system for analyzing polymorphonuclear leukocyte chemotaxis in patients with diabetes mellitus.

A computer-assisted image-analysis system that precisely tracks the cell movements of up to 50 polymorphonuclear leukocytes (PMNLs) was developed and used to quantitatively measure cellular chemokinesis and chemotaxis in normal individuals and in diabetic patients with hyperglycemia. The PMNLs were tested in Zigmond chambers with or without a gradient of 10(-7) M n-formylmethionylleucylphenylalanine (f-Met-Leu-Phe). Cellular movement was recorded on videotape by using a videocamera mounted on the microscope. The videotapes were analyzed by computer programs to calculate the speed and direction of each PMNL at 10-sec intervals. Average rates of chemokinesis were 19.6 microns/min without and 25.3 microns/min with f-Met-Leu-Phe. McCutcheon indices, which measure chemotaxis, were 0.01 without and 0.48 with f-Met-Leu-Phe. Similar values were observed in diabetic patients after fasting (average glucose, 217 mg/100 ml) and 2 hr after glucose challenge (average glucose, 309 mg/100 ml). These values demonstrate that PMNLs from diabetic patients with hyperglycemia move at normal rates and respond appropriately to f-Met-Leu-Phe.

Adolescent↗

DNA content and chromatin texture of benzo[a]pyrene-transformed human breast epithelial cells as assessed by image analysis.

DNA content and chromatin supraorganization defined in terms of patterns of chromatin texture were studied by image analysis in Feulgen-stained human breast MCF-10F epithelial cells expressing different stages of tumorigenic progression after treatment with benzo[a]pyrene (BP). Nontransformed MCF-10F, nontumorigenic transformed BP1, and tumorigenic BP1-E1 cell lines were analyzed. A relationship between changes in DNA content and chromatin texture and the expression of different stages of tumorigenesis were researched in interphase nuclei. A significant decrease in Feulgen-DNA amounts and absorbing areas suggesting aneuploidy, and first detected in nontumorigenic transformed BP1 cells, became more relevant in the tumorigenic cell line BP1-E1. Simultaneously, an increase in optical densities and a change in related parameters, demonstrating increased chromatin higher order packing states, occurred in transformed BP1 cells and extended over larger chromatin areas in tumorigenic BP1-E1 cells. The results indicate loss of DNA and a change in chromatin higher order packing states accompanying the expression of different stages of the in vitro tumorigenesis process in BP-transformed human breast epithelial cells. It is suspected that the gradually acquired chromatin "condensation" supraorganization pattern is associated with activated transcription activities previously suggested for these cells.

Benzo(a)pyrene↗

Computer-assisted image analysis of caveolin-1 involvement in the internalization process of adenosine A2A-dopamine D2 receptor heterodimers.

A functional aspect of horizontal molecular networks has been investigated experimentally, namely the heteromerization between adenosine A2A and dopamine D2 receptors and the possible role of caveolin-1 in the co-trafficking of these molecular complexes. This study has been carried out by means of computer-assisted image analysis procedure of laser images of membrane immunoreactivity of caveolin-1, A2A, D1, and D2 receptors obtained in two clones of Chinese hamster ovary cells one transfected with A2A and dopamine D1 receptors and the other one with A2A and D2 receptors. Cells were treated for 3 h with 10 microM D1 receptor agonist SKF 38393, 50 microM D2-D3 receptor agonist quinpirole, and 200 nM A2A receptor agonist CGS 21680. In A2A-D1-cotransfected cells, caveolin-1 was found to colocalize with both A2A and D1 receptors and treatment with SKF 38393 induced internalization of caveolin-1 and D1 receptors, with a preferential internalization of D1 receptors colocalized with caveolin-1. In A2A-D2-cotransfected cells, caveolin-1 was found to colocalize with both A2A and D2 receptors and either CGS 21680 or quinpirole treatment induced internalization of caveolin-1 and A2A and D2 receptors, with a preferential internalization of A2A and D2 receptors colocalized with caveolin-1. The results suggest that A2A and D2 receptors and caveolin-1 likely interact forming a macrocomplex that internalizes upon agonist treatment. These observations are discussed in the frame of receptor oligomerization and of the possible functional role of caveolin-1 in the process of co-internalization and, hence, in controlling the permanence of receptors at the plasma membrane level (prerequisite for receptor mosaic organization and plastic adjustments) and in the control of receptor desensitization.

Animals↗

The cross sectional area of diaphragmatic muscle fibres in emphysema, measured by an automated image analysis system.

The cross-sectional area of diaphragmatic muscle fibres was measured using a Quantimet 720 image analysis system in 18 patients with emphysema and six control non-emphysematous patients. The technique proved to be an accurate method of measuring muscle fibre area and much more rapid than the previously described methods. The mean cross-sectional area of the muscle fibres in the emphysematous group was 1069-5 mum2 and this was significantly greater than the mean of the control group which was 851-0 mum2. In the emphysematous group nine patients who died from chronic airways obstruction had a larger mean muscle fibre area than the nine patients with non-fatal respiratory disease. The emphysematous patients showed a marked increase in the number of very large muscle fibres (2000-2200 mum2) in the diaphrahm and also an increased variation in size from fibre to fibre. The increase in muscle fibre size showed a positive correlation with ventricular weight but not with the amount of emphysema in the lungs. It would appear that although the excursion of the diaphragm is reduced in emphysema the muscle fibres do not atrophy but in fact undergo work hypertrophy. This is presumably due to the horizontal shortening of the muscle fibres, when the diaphragm is working at a poor mechanical advantage, because it cannot descend normally in emphysematous patients.

Adolescent↗

Hyperplasia of Type 2 pneumocytes following 0.34 ppm nitrogen dioxide exposure: quantitation by image analysis.

Swiss Webster male mice were exposed to intermittent 0.34 ppm nitrogen dioxide for 6 wk. Quantitative image analysis showed increased Type 2 cell numbers in each of the three lobes measured, with and without adjustment to alveolar wall measurements for lung volume normalization (e.g., P less than .037 for Type 2 cell number adjusted to alveolar wall perimeters, combined lobe analysis of variance). The exposed animals dominated the upper quartile ranking of the cell number/alveolar area ratio computations (P less than .025), which implied the presence of an especially susceptible subpopulation of animals. The Type 2 cell increase is believed to result from damage and loss of Type 1 cells, the reversibility and progression of which are presently unknown. The data also suggest an increased size of the Type 2 cell, and possibly slight atelectasis and/or edema of the alveolar walls.

Animals↗